1. Field of the Invention
The invention relates to oscillator circuit shaving input protection networks.
2. Brief Description of the Prior Art
It is well known that when MOS or CMOS devices are handled, the high impedance gate inputs must be protected from static electricity over-voltages. The breakdown voltage of the gate insulator of typical CMOS devices is approximately 80 volts. Numerous input protection circuits have been utilized to dissipate static electricity over-voltages. Many of these input protection devices have utilized PN diodes in integrated circuit structures. Such protection devices are effective, but in certain instances feedback from the internal portions of an oscillator circuit may be desired to boost the protected node beyond the supply voltage limits. The known protection diode arrangements clamp the protected node to within a diode voltage drop from the supply voltages. Such clamping is undesirable in certain cases and prevents use of certain useful circuit design techniques.